This invention relates generally to systems for spreading particulate materials. More particularly, this invention relates to a system for spreading particular amounts of particulate materials in an even manner across different surfaces.
There are several devices currently known to the landscaping industry which perform an effective job of distributing particulate materials across open spaces such as grass fields. One such device comprises a hopper with a rotary vane attached underneath that can spread particulate materials in all directions as the hopper is pushed forward or backward. Although such devices are adequate for wide-open spaces, they have several shortcomings in other situations. For example, there is often a need to spread fertilizer, pesticides, or other materials along the underside of shrubbery or garden plants. Because concentrated fertilizer can be corrosive and can damage plant tissue because of chemical burning, there is a need for a way to uniformly apply fertilizer below the leaves of the plants while avoiding placing any fertilizer on top of the leaves. Because common hopper-type spreaders cannot perform this task adequately, landscape maintenance workers often have to perform this task by hand by dipping a cup or other container into a hopper or bag and then distribute the material by hand to the underside of the shrubbery. This process can be very cumbersome and time-consuming, and it is very difficult to guarantee that the particulate materials are evenly distributed over the intended surfaces. When a worker uses this process, some areas will often get no particulate material at all, while other areas will get too much material. Additionally, if the worker is not careful or is in a hurry, fertilizer could accidentally be thrown onto the leaves of the plant, causing serious damage to the plant. Finally, distributing the fertilizer by hand can cause the worker to accidentally spill material upon himself, which can create an unprofessional image of the worker or pose health risks depending upon the composition of the fertilizer.
Similar problems exist for other particulate materials. For example, it is often desirable to evenly distribute grass seed in corners or hard-to-reach areas of a plot of land. Additionally, it can also be important to distribute salt or urea on icy and snowy pavement or sidewalk during the winter months. Although there are several products currently on the market that perform an adequate job of distributing these materials along roads, these devices often have a difficult time reaching non-flat, paved areas such as steps or corners. If the salt or urea is not adequately distributed on such surfaces, portions of the surfaces can remain icy and slippery and could result in serious harm to someone who walks on the surfaces. As in the case of the landscape maintenance worker, people often spread the materials by hand to reach difficult places. But this can be very time-consuming and it is difficult to ensure that the material is evenly spread across the surfaces.
There are still other areas where there is a need for evenly spreading particulate materials while maintaining precise control of where the materials are deposited. For example, golf course maintenance personnel often need to spread dry sand in sand traps and other areas. In these situations, a user""s options are often quite limited in how they can efficiently and adequately spread the materials in an even manner.
It is also important that a person who is spreading particulate materials can do so over a large area quickly and efficiently. In the case of a large plot of land, a worker must often spread particulate materials in many different locations in hard to reach areas.
There have been attempts to develop systems for spreading particulate materials in an even manner, but each has its drawbacks. In particular, several devices use a combination of a rotary vane and a blower motor to power the spreader through a large boom. Blower motors are an inefficient means of forcing air at a velocity sufficient to force the particulate materials out of the boom, however, and such systems would require air hoses with a diameter of about two to four inches. These devices can also be so large and heavy that they must be mounted in the bed of a compact pick-up truck in order to be transported. Furthermore, the exit channels on many of these devices are fixed in position relative to the rest of the device and have a limited range direction when spreading the materials.
It is therefore an object of this invention to provide an improved system for spreading particulate materials across surfaces in an evenly-distributed manner.
It is another object of this invention to provide an improved system for spreading particulate materials in which the user can precisely control the direction in which the materials are spread.
It is another object of this invention to provide a system for spreading particulate materials that can be adapted to spread materials of different densities and particle sizes.
It is yet another object of this invention to provide a vehicle-mounted system for spreading particulate materials.
It is yet another object of this invention to provide an system for spreading particulate materials that can spread the materials in more than one direction at one time.
It is yet another object of this invention to provide a system for applying particulate materials wherein the user has the ability to quickly activate or discontinue the flow of the particulate material.
It is yet another object of this invention to provide a system for spreading particulate materials wherein the amount of material that is distributed can be quickly adjusted.
It is yet another object of this invention to provide a system for spreading particulate materials wherein the system can make adjustments to ensure that a constant amount of material is being distributed over time.
It is still another object of this invention to provide a system for spreading particulate materials wherein the apparatus can be easily operated.
To obtain the above-described objects, one aspect of this invention provides for a particulate spreader comprising an engine which supplies energy to a compressor. The compressor compresses air or other compressible fluid in a pressurized supply source, and the pressurized gas flows from the supply source into a chamber or metering block through a pressurized gas entrance conduit. At the same time, particulate material from a material hopper is deposited into the metering block. The particulate material is carried or entrained by the pressurized gas into an exit conduit, preferably in the form of a flexible hose with a wand at the end thereof. Both the air flow and the flow of particulate material can be modified by manually adjusting a series of valves. The preferred engine-compressor combination includes a feedback loop for maintaining the air pressure within a certain range. A user holds the exit conduit at a handle and points the wand in the appropriate direction and activates a switch in the handle for starting the flow of gaseous material to the metering block, spreading the particulate material in the desired location. The user also operates the switch when it is desired to stop the spreading operation by discontinuing the flow of air into the metering block. The switch and valve can also be modified to maintain a partial flow of air into the metering block.
According to another aspect of the invention, one engine and one compressor are used to supply compressed air to two separate metering blocks. Each metering block has an exit conduit connected to it so that particulate materials can be spread in multiple directions at one time.
These and other objects, advantages, and features of the invention, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like elements have like characters throughout the drawings described below.